A toolset for 3D in vitro tissue engineering

Abstract: Tissue-engineered approaches are required to better understand the causes of renal failure and for the development of new treatment options. Upon renal failure, due to acute or chronic causes, renal replacement therapies such as dialysis or transplantation are necessary to restore function. Currently, 185,000 Americans have a functioning kidney transplant and 450,000 are on dialysis. How... read moreever, recapitulating the functions of the human kidney in vitro remains challenging due to the anatomical complexity required to mimic renal physiology. Despite these challenges, advancements in microfluidic and 3D tissue culture techniques have demonstrated the importance of both microenvironment and mechanosensory stimulation in establishing physiologically relevant, in vitro models for disease studies and drug development. Accordingly, we have developed a 3D in vitro tissue toolset that can be utilized to achieve the necessary phenotypes for studying kidney development and disease. In order to understand the development of polycystic kidney disease we established static hydrogel cultures to characterize long-term development of cysts and changes in structural morphologies. Additionally, we developed a modular, three dimensional perfusion culture system to support the controlled fluidic stimulation of a planar cell layer seeded on a 3D porous, silk protein scaffold. Lastly, we established a simple, robust assay for the in vitro formation of renal epithelial tubules by a telomerase immortalized human proximal tubule cell line (RPTEC/tert1). This methodology yields polarized, luminal tubules that were responsive to TGFβ stimulation and co-culture with stromal cells. These in vitro model systems, which yield physiologically relevant phenotypes without complex differentiation protocols or culture methods, comprise a necessary toolset for future in vitro studies of disease pathogenesis and nephrotoxicity. read less